The present disclosure relates generally to electronic messaging systems and, more particularly, to an electronic message delivery system for processing electronic messages from a sender to a recipient through the Internet.
Today, the most prevalent form of electronic messaging, email, is a mission critical service operating on networks; and email traffic and management complexity is rapidly increasing. As network operators look to respond to capacity and complexity challenges while managing the size of their email networks and the cost of operating them, there is a strong and growing demand for better solutions.
Email is a form of electronic communication between servers that is defined by a communication protocol called Simple Mail Transport Protocol (SMTP). The SMTP protocol is the communication mechanism by which email messages are commonly moved from one server to another, and involves a multi-step exchange of information between two servers for the transmission of a message from one to the other. Similar protocols are used for other types of electronic messaging (e.g. SMS).
It is commonly known that there are seven layers to the Open System Interconnection model, also known as the OSI model, which describes the multi-layered operating environment of computer systems and networks. Each layer represents a step of abstraction above the next, from the lowest level machine code than runs bits and bytes on the hardware (Layer 1 or “Physical Layer”) to the highest layer (Layer 7 or “Application Layer”). An example of a traditional, computer network system based on the OSI model is illustrated in FIG. 1. FIG. 1 shows a computer network system 10, including a physical layer 12 (Layer 1), a data link layer 14 (Layer 2), a network layer 16 (Layer 3), a transport layer 18 (Layer 4), a session layer 20 (Layer 5), a presentation layer 22 (Layer 6) and an application layer 24 (Layer 7). As indicated by a series of arrows 30, each layer communicates only with the immediately adjacent layer. That is, information is exchanged only between adjacent layers in a typical OSI system.
SMTP and other electronic message protocols are executed via software applications that run on the highest layer, Layer 7 (or application layer 24, as shown in FIG. 1). Many important functions of electronic traffic routing and security are conducted at the level at which data packet transactions occur, Layer 3 (i.e., network layer 3, as shown in FIG. 1). This is the arena of operation for the primary functions of many network devices including routers, switches, firewalls and others.
In a typical email system, the email server, or mail transport agent (MTA), operates solely on Layer 7. In a network containing an email system, the Network Layer, Layer 3, typically acts on network traffic (e.g. to route data packets) with no regard to application related protocols or requirements and no interaction with message-related functions or settings. Thus, for email and other message traffic, routing and security functions (e.g. priority, traffic access, bandwidth allocation, fail-over, data encryption, relay etc.) are performed separately, using independently determined criteria and wholly independent actions at Layer 3 and Layer 7. Any relevant traffic flow or security information gathered at one layer is visible only to, and actionable only on, that layer.
A standard network configuration for electronic messaging consists of a message transport server (e.g. MTA) and a network device for routing data into and out of the network (e.g. switch). The MTA and network device are configured separately and do not communicate. An example of such a standard network configuration is shown in FIG. 4A. FIG. 4A illustrates a prior art electronic messaging system 50, including an MTA 52 connected via a network device 54 to Internet 56. MTA 52 and network device 54 communicate by an SMTP link 58 (indicated by a double-headed arrow), and network device 54 is connected to Internet 56 by another SMTP link 60 (indicated by another double-headed arrow). Network device 54 may include an API or command interface 62, but interface 62 is not directly connected with MTA 52 nor Internet 62.